782 REPORT — 1902. 



These delieate-'beaded branches and also fine-headed branches, which come off 

 in great numbers from the coarser branches (giving them a shaggy appearance), 

 form the intercellular plexus. 



4. Collaterals given oflF from the axis cylinders, probably of pyramidal cells, 

 can also be demonstrated to join to the network. 



5. The Intercellular Plexus. — This consists of a dense mass of extremely fine- 

 beaded fibrils intersecting each other in all directions, but probably not joining at 

 the intersections. 



It can be demonstrated to proceed from the dendrites of the dark cells and to 

 pass to the pericellular network. In fact the network is merely an extension of 

 the plexus, but apparently except at this network the individual fibres which 

 meet together on all sides to form it do not join but merely overlap. 



This plexus differs essentially from those conceived by (but never demonstrated) 

 Gerlach, Golgi, or Nevil, inasmuch as it is not a derivative from the protoplasmic 

 processes of the pyramidal cells and is only indirectly concerned with these celb 

 by means of the junctions of the collaterals already referred to, and which 

 probably are given off from the axis cylinders of the pyramidal cells. 



Conclusion. 

 The above observations show : — 



(1) That there is a system of cortical nerve-cells which, by means of their 

 protoplasmic processes, are in organic continuity, through the medium of a peri- 

 cellular network which envelopes the pyramidal cells. 



(2) That collaterals, arising in all probability from the axes cylinders of the 

 pyramidal cells, also join on to this network. 



(3) And that therefore practically all the nerve-cells of the cortex are in 

 organic continuity. 



(4) It is suggested that the difference in staining, shape, «S;c., of the two 

 varieties of cells implies a corresponding difference in function, and as we have 

 good ground for associating the pyi-amidal cells with motor functions, that the 

 dark cells are associated with sensory functions — in other words that they are 

 bearers and distributors of afferent stimuli, and that by this method, therefore^ 

 we have a means of showing where ingoing currents end and where outgoing 

 currents are initiated. 



(5) But if the dark cells are bearers of afferent stimuli this further implies- 

 that nerve-currents do not invariably flow in one direction — viz., from the dendrites 

 to the cell and from the cell out by way of the axis cylinder, a view very generally 



held but that in some cases it flows into the cell by the axis cylinder and out by 



the dendrites. 



6. The Nervous System of the Camel, 

 By W. Page May, M.D. 



7. Regeneration of Nerves. 

 By W. D. Halliburton, M.D., F.R.S., and F. W. Mott, M.D., F.R.S. 



Some experiments which we performed on the nerves of cats, and which had 

 for their object the study of the process of degeneration in nerve-fibres, have led 

 us durinc the past year to take up the related question of regeneration. 



From the microscopic study of the distal portions of divided nerve-trunks we 

 arrived at the conclusion that the activity of the neurilemmal cells has some rela- 

 tion to the development of the new nerve-fibres. These cells elongate and become 

 connected end to end, and thus lead to the formation of what look like embryonic 

 nerve-fibres. 



Those who have worked at the regeneration of nerve-fibres may be divided into 

 two schools : those who believe that the new fibres sprout out from the central 



